Layered inductor and layered inductor array

Abstract

To reduce a difference in DC resistance and / or inductance value of each of a plurality of coil conductors, in an inductor including the coil conductors inside.SOLUTION: A layered inductor of the present disclosure includes: an element assembly 10 constituted by laminating a plurality of magnetic layers ML in a lamination direction; external electrodes E1-E4 provided on a bottom face of the element assembly 10; winding parts W1, W2 formed by connecting each end of a plurality of conductors C1, C2, respectively, by a via V, the conductors being disposed in layers different from each other of the element assembly 10; and coils 21, 22 including through holes T1-T4, respectively. The conductors C1, C2 are provided in the same layer, and the area of the conductor C1 in the same layer in plan view is approximately equal to the area of the conductor C2 in plan view. As viewed in a direction crossing the lamination direction, the conductor C1 and the conductor C2 are alternately disposed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to stacked inductors and stacked inductor arrays. [Background technology]

[0002] In recent years, as equipment becomes more sophisticated, the DC-DC converters in voltage conversion circuits are becoming larger in current and more efficient, and the rated current of the power inductors used in these devices is also increasing.

[0003] Patent Document 1, which shows an example of the above-mentioned inductor, discloses a coil component comprising a first coil conductor provided in a first insulating body and a second coil conductor provided in a second insulating body, in which a first coil surface of the first coil conductor faces a second coil surface of the second coil conductor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-067883 A Summary of the Invention [Problem to be solved by the invention]

[0005] As described in Patent Document 1, when a coil component includes a first coil conductor and a second coil conductor, a direct current resistance (R dc ) and / or inductance values.

[0006] The present disclosure has been made in view of the above problems. That is, a main objective of the present disclosure is to reduce the difference in the DC resistance and / or inductance value of each coil conductor in an inductor having multiple coil conductors therein. [Means for solving the problem]

[0007] The laminated inductor of the present disclosure comprises: an element body formed by laminating a plurality of magnetic layers in a lamination direction; a first external electrode, a second external electrode, a third external electrode and a fourth external electrode provided on a bottom surface of the element body; a first coil including a first winding portion formed by connecting respective ends of a plurality of first conductors arranged on different layers of the element body with vias, a first through hole connecting one end of the first winding portion relatively close to the bottom surface and the first external electrode, and a second through hole connecting the other end of the first winding portion relatively far from the bottom surface and the second external electrode; a second coil including a second winding portion formed by connecting respective ends of a plurality of second conductors arranged on different layers of the element body by vias, a third through hole connecting one end of the second winding portion relatively close to the bottom surface and the third external electrode, and a fourth through hole connecting the other end of the second winding portion relatively far from the bottom surface and the fourth external electrode, the first conductor and the second conductor are provided in the same layer, and an area of ​​the first conductor in a plan view in the same layer is substantially equal to an area of ​​the second conductor in a plan view; When viewed from a direction intersecting the stacking direction, the first conductors and the second conductors are arranged alternately with each other.

[0008] Moreover, the laminated inductor array of the present disclosure has an element body formed by laminating a plurality of magnetic layers in a lamination direction; a first external electrode, a second external electrode, a third external electrode, a fourth external electrode, a fifth external electrode, a sixth external electrode, a seventh external electrode and an eighth external electrode provided on a bottom surface of the element body; a first coil including a first winding portion formed by connecting respective ends of a plurality of first conductors arranged on different layers of the element body with vias, a first through hole connecting one end of the first winding portion relatively close to the bottom surface and the first external electrode, and a second through hole connecting the other end of the first winding portion relatively far from the bottom surface and the second external electrode; a second coil including: a second winding portion formed by connecting respective ends of a plurality of second conductors arranged on different layers of the element body with vias; a third through hole connecting one end of the second winding portion relatively close to the bottom surface and the third external electrode; and a fourth through hole connecting the other end of the second winding portion relatively far from the bottom surface and the fourth external electrode; a third coil including: a third winding portion formed by connecting respective ends of a plurality of third conductors arranged on different layers of the element body with vias; a fifth through hole connecting one end of the third winding portion relatively close to the bottom surface and the fifth external electrode; and a sixth through hole connecting the other end of the third winding portion relatively far from the bottom surface and the sixth external electrode; a fourth coil including a fourth winding portion formed by connecting respective ends of a plurality of fourth conductors arranged on different layers of the element body with vias, a seventh through hole connecting one end of the fourth winding portion relatively close to the bottom surface and the seventh external electrode, and an eighth through hole connecting the other end of the fourth winding portion relatively far from the bottom surface and the eighth external electrode, the third coil and the fourth coil are adjacent to each other in a direction intersecting the stacking direction with respect to the first coil and the second coil, the first conductor and the second conductor are provided in the same layer, and an area of ​​the first conductor in a plan view in the same layer is substantially equal to an area of ​​the second conductor in a plan view; When viewed from a direction intersecting the stacking direction, the first conductors and the second conductors are arranged alternately with each other, the third conductor and the fourth conductor are provided in the same layer, and an area of ​​the third conductor in a plan view in the same layer is substantially equal to an area of ​​the fourth conductor in a plan view; When viewed from a direction intersecting the stacking direction, the third conductors and the fourth conductors are arranged alternately with each other. Effect of the Invention

[0009] According to the present disclosure, in an inductor having multiple coils therein, the difference in the DC resistance and / or inductance value of each coil can be reduced. Specifically, the first conductor and the second conductor are provided in the same layer, the area of ​​the first conductor in a plan view in the same layer is approximately equal to the area of ​​the second conductor in a plan view, and the first conductor and the second conductor are alternately arranged when viewed from a direction intersecting the stacking direction, so that the coils have similar shapes and the wiring lengths can be approximately equal. Therefore, the difference in the DC resistance and / or inductance value of each coil can be reduced. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view illustrating a schematic example of a laminated inductor according to the present disclosure. [Diagram 2] FIG. 2 is a perspective view that illustrates an example of the first coil and the second coil of the present disclosure. [Diagram 3] FIG. 3 is an exploded perspective view showing a schematic example of the internal structure of the laminated inductor of the present disclosure. [Figure 4] FIG. 4 is a cross-sectional view illustrating a schematic example of a laminated inductor according to the present disclosure. [Diagram 5] FIG. 5 is a cross-sectional view that illustrates a schematic example of another laminated inductor according to the present disclosure. [Figure 6] FIG. 6 is a perspective view illustrating a schematic example of a laminated inductor array according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The laminated inductor of the present disclosure will be described below. Note that the present disclosure is not limited to the following configurations, and may be modified as appropriate without departing from the gist of the present disclosure. In addition, a combination of multiple individual preferred configurations described below also constitutes the present disclosure.

[0012] The laminated inductor of the present disclosure is used in, for example, a DC-DC converter, but can also be used in applications other than DC-DC converters.

[0013] In this specification, terms indicating the relationship between elements (e.g., "parallel," "orthogonal," etc.) and terms indicating the shapes of elements do not only mean the strict literal form, but also mean a range that is substantially equivalent, for example, a range that includes a difference of about a few percent. Note that in this specification, the direction in which the magnetic layers and coil conductors that make up the element body are stacked is referred to as the "stacking direction."

[0014] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, and scale may differ from those of the actual product.

[0015] <Multilayer inductor> First, one embodiment of the laminated inductor of the present disclosure will be described with reference to Figures 1 to 4. Note that the shape and arrangement of the laminated inductor and each of its components are not limited to the example shown in the drawings.

[0016] 1 includes an element body 10, a first external electrode E1, a second external electrode E2, a third external electrode E3, and a fourth external electrode E4 provided on the bottom surface of the element body 10, a first coil 21, and a second coil 22. Each component will be described in detail below.

[0017] -Base body- The element body 10 has, for example, a rectangular parallelepiped shape or a substantially rectangular parallelepiped shape having six sides. The corners and ridges of the element body 10 may be rounded. The corners are portions where three sides of the element body 10 intersect, and the ridges are portions where two sides of the element body 10 intersect.

[0018] 1, the length direction, width direction, and height direction of the laminated inductor 1A and the element body 10 are shown as L direction, W direction, and T direction, respectively. The length direction L, width direction W, and height direction T are perpendicular to each other. The mounting surface of the laminated inductor 1A is, for example, a surface (LW surface) parallel to the length direction L and width direction W.

[0019] 1 has a first main surface 11 and a second main surface 12 facing in a height direction T, a first end surface 13 and a second end surface 14 facing in a length direction L, and a first side surface 15 and a second side surface 16 facing in a width direction W. In the example shown in Fig. 1, a first external electrode E1, a second external electrode E2, a third external electrode E3, and a fourth external electrode E4 are formed on the first main surface 11 of the element body 10, which corresponds to the mounting surface (bottom surface) of the element body 10.

[0020] The element body 10 is configured by stacking a plurality of magnetic layers ML in the stacking direction. The element body 10 may include a first coil 21 having a first conductor C1 and a second coil 22 having a second conductor C2, which will be described later. In this embodiment, as shown in FIG. 3, the element body 10 is configured by stacking multilayer groups G1 to G10 and forming external electrodes E1 to E4 on the lower side of the multilayer group G10. Note that the boundaries between the layers in the multilayer structure of the element body 10 may disappear. Also, each of the multilayer groups G1 to G10 may be configured by stacking a plurality of layers of the same pattern.

[0021] The lamination group G1 includes a magnetic layer ML and may form the second main surface 12 of the element body .

[0022] The multilayer group G2 includes a magnetic layer ML and a first conductor C1 and a second conductor C2 arranged in the same layer. The area of ​​the first conductor C1 in plan view from the stacking direction in the same layer is approximately equal to the area of ​​the second conductor C2 in plan view from the stacking direction. Here, approximately equal includes a range of ±10%, and more preferably, may be within ±5%. The area of ​​the first conductor C1 and the area of ​​the second conductor C2 can be calculated using an image analysis function from a photograph obtained by, for example, photographing the surface of the multilayer group obtained by polishing an inductor sample parallel to the LW with a digital microscope.

[0023] The first conductor C1 of the multilayer group G2 may be disposed along two sides forming a corner of the magnetic layer ML (for example, a corner close to the third external electrode E3 in a planar perspective). That is, the first conductor C1 may be formed in an L-shape in a planar view seen from the stacking direction. A second through-hole (not shown) connected to the second external electrode E2 may be provided at one end of the first conductor C1 (for example, an end close to the second external electrode E2 in a planar perspective). In addition, a via (not shown) connected to the first via V1 of the multilayer group G3 may be provided at the other end of the first conductor C1 (for example, an end close to the fourth external electrode E4 in a planar perspective). Note that the end includes not only the tip end portion but also the area near the tip end.

[0024] The second conductor C2 of the multilayer group G2 may be disposed along two sides forming the other corner of the magnetic layer ML (for example, the corner close to the first external electrode E1 in a planar perspective). That is, the second conductor C2 may be formed in an L-shape in a planar view seen from the stacking direction. A via (not shown) that connects to the second via V2 of the multilayer group G3 may be provided at one end of the second conductor C2 (for example, the end close to the second external electrode E2 in a planar perspective). In addition, a fourth through-hole (not shown) that connects to the fourth external electrode E4 may be provided at the other end of the second conductor C2 (for example, at a position close to the fourth external electrode E4 in a planar perspective).

[0025] The stacking group G3 may include a magnetic layer ML, a first via V1 connecting adjacent first conductors C1 in the stacking direction, a second via V2 connecting adjacent second conductors C2 in the stacking direction, a second through hole T2, and a fourth through hole T4.

[0026] The first via V1 of the multilayer group G3 may be disposed at a position where it is connected to the other end (the end close to the fourth external electrode E4 in a planar perspective view) of the first conductor C1 of the multilayer group G2 described above. The first via V1 of the multilayer group G3 may be disposed adjacent to the fourth through hole T4 in a planar view seen from the stacking direction at a distance that ensures electrical insulation from the fourth through hole T4.

[0027] The second via V2 of the multilayer group G3 may be disposed at a position where it is connected to one end (the end close to the second external electrode E2 in a planar perspective view) of the second conductor C2 of the multilayer group G2 described above. The second via V2 of the multilayer group G3 may be disposed adjacent to the second through hole T2 in a planar view seen from the stacking direction at a distance that ensures electrical insulation from the second through hole T2.

[0028] The second through hole T2 of the multilayer group G3 may be electrically connected to the second external electrode E2 by connecting the second through holes T2 of the multilayer groups G2 and G4 adjacent to each other in the stacking direction. Therefore, the second through hole T2 may be disposed on the second external electrode E2 in a planar perspective view.

[0029] The fourth through hole T4 of the multilayer group G3 may be electrically connected to the fourth external electrode E4 by connecting the fourth through holes T4 of the multilayer groups G2 and G4 adjacent in the stacking direction. Therefore, the fourth through hole T4 may be disposed on the fourth external electrode E4 in a planar perspective view.

[0030] The multilayer group G4 may include a magnetic layer ML, a first conductor C1 and a second conductor C2 arranged in the same layer, a second through hole T2, and a fourth through hole T4. The area of ​​the first conductor C1 in a plan view from the stacking direction in the same layer is approximately equal to the area of ​​the second conductor C2 in a plan view from the stacking direction. Here, approximately equal includes a range of ±10%, and may be within ±5%, more preferably.

[0031] The first conductor C1 of the multilayer group G4 may be connected to the first conductor C1 of the multilayer group G2 through the first via V1 of the multilayer group G3, and may constitute a part of the winding of the first coil 21. Specifically, the first conductor C1 of the multilayer group G4 may have an avoidance portion A along at least one side of the magnetic layer ML located opposite to the side of the magnetic layer ML along the first conductor C1 of the multilayer group G2 in a plan view seen from the stacking direction, and avoids the fourth through hole T4. A specific embodiment of the avoidance portion A will be described later. A via (not shown) that connects to the first via V1 of the multilayer group G5 may be provided at one end of the first conductor C1 (the end close to the second external electrode E2 in a planar perspective view). In addition, the other end of the first conductor C1 (the end close to the fourth external electrode E4 in a planar perspective view) may be connected to the first via V1 of the multilayer group G3.

[0032] The second conductor C2 of the multilayer group G4 may be connected to the second conductor C2 of the multilayer group G2 through the second via V2 of the multilayer group G3, and may constitute a part of the winding of the second coil 22. Specifically, the second conductor C2 of the multilayer group G4 may be along at least one side of the magnetic layer ML located opposite to the side of the magnetic layer ML along the second conductor C2 of the multilayer group G2 in a plan view seen from the stacking direction, and may have an avoiding portion A that avoids the second through hole T2. One end of the second conductor C2 (an end close to the second external electrode E2 in a planar perspective view) may be connected to the second via V2 of the multilayer group G3. In addition, the other end of the second conductor C2 (an end close to the fourth external electrode E4 in a planar perspective view) may be provided with a via (not shown) that connects to the second via V2 of the multilayer group G5.

[0033] The second through hole T2 of the multilayer group G4 may be electrically connected to the second external electrode E2 by connecting the second through holes T2 of the multilayer groups G3 and G5 adjacent to each other in the stacking direction. Therefore, the second through hole T2 may be disposed at a corner of the magnetic layer ML located on the second external electrode E2.

[0034] The fourth through hole T4 of the multilayer group G4 may be electrically connected to the fourth external electrode E4 by connecting the fourth through holes T4 of the multilayer groups G3 and G5 adjacent to each other in the stacking direction. Therefore, the fourth through hole T4 may be disposed at a corner of the magnetic layer ML located on the fourth external electrode E4.

[0035] The stacking group G5 may include a magnetic layer ML, a first via V1 connecting adjacent first conductors C1 in the stacking direction, a second via V2 connecting adjacent second conductors C2 in the stacking direction, a second through hole T2, and a fourth through hole T4.

[0036] The first via V1 of the multilayer group G5 may be disposed at a position where it is connected to one end of the first conductor C1 of the multilayer group G4 described above. The first via V1 of the multilayer group G5 may be provided on the side of the magnetic layer ML opposite to the side of the first via V1 of the multilayer group G3 in a planar perspective view.

[0037] The second via V2 of the multilayer group G5 may be disposed at a position where it is connected to one end of the second conductor C2 of the multilayer group G4 described above. The second via V2 of the multilayer group G5 may be provided on the side of the magnetic layer ML opposite to the second via V2 of the multilayer group G3 in a planar perspective view.

[0038] The second through hole T2 of the multilayer group G5 may be electrically connected to the second external electrode E2 by connecting the second through holes T2 of the multilayer groups G4 and G6 adjacent to each other in the stacking direction. Therefore, the second through hole T2 may be disposed at a corner of the magnetic layer ML located on the second external electrode E2 in a planar perspective view.

[0039] The fourth through hole T4 of the multilayer group G5 may be electrically connected to the fourth external electrode E4 by connecting the fourth through holes T4 of the multilayer groups G4 and G6 adjacent to each other in the stacking direction. Therefore, the fourth through hole T4 may be disposed at a corner of the magnetic layer ML located on the fourth external electrode E4 in a planar perspective view.

[0040] The multilayer group G6 may include a magnetic layer ML, a first conductor C1 and a second conductor C2 arranged in the same layer, a second through hole T2, and a fourth through hole T4. The area of ​​the first conductor C1 in a plan view from the stacking direction in the same layer is approximately equal to the area of ​​the second conductor C2 in a plan view from the stacking direction. Here, approximately equal includes a range of ±10%, and may be within ±5%, more preferably.

[0041] The first conductor C1 of the multilayer group G6 may be connected to the first conductor C1 of the multilayer group G4 through the first via V1 of the multilayer group G5, and may constitute a part of the winding of the first coil 21. Specifically, the first conductor C1 of the multilayer group G6 may be along at least one side of the magnetic layer ML located opposite to the side of the magnetic layer ML along the first conductor C1 of the multilayer group G4 in a plan view seen from the stacking direction, and may have an avoiding portion A that avoids the second through hole T2. One end of the first conductor C1 may be connected to the first via V1 of the multilayer group G5. In addition, a via (not shown) that connects to the first via V1 of the multilayer group G7 may be provided at the other end of the first conductor C1.

[0042] The second conductor C2 of the multilayer group G6 may be connected to the second conductor C2 of the multilayer group G4 through the second via V2 of the multilayer group G5, and may form a part of the winding of the second coil 22. Specifically, the second conductor C2 of the multilayer group G6 may be along at least one side of the magnetic layer ML located opposite to the side of the magnetic layer ML along the second conductor C2 of the multilayer group G4 in a plan view seen from the stacking direction, and may have an avoiding portion A that avoids the fourth through hole T4. One end of the second conductor C2 may be provided with a via (not shown) that connects to the second via V2 of the multilayer group G7. The other end of the second conductor C2 may be connected to the second via V2 of the multilayer group G5.

[0043] The second through hole T2 of the multilayer group G6 may be electrically connected to the second external electrode E2 by connecting the second through holes T2 of the multilayer groups G5 and G7 adjacent to each other in the stacking direction. Therefore, the second through hole T2 may be disposed at a corner of the magnetic layer ML located on the second external electrode E2.

[0044] The fourth through hole T4 of the multilayer group G6 may be electrically connected to the fourth external electrode E4 by connecting the fourth through holes T4 of the multilayer groups G5 and G7 adjacent to each other in the stacking direction. Therefore, the fourth through hole T4 may be disposed at a corner of the magnetic layer ML located on the fourth external electrode E4.

[0045] The multilayer group G7 may include a magnetic layer ML, a first via V1 connecting the first conductors C1 to each other, a second via V2 connecting the second conductors C2 to each other, a second through hole T2, and a fourth through hole T4.

[0046] The first via V1 of the multilayer group G7 may be disposed at a position where it is connected to the other end (the end close to the third external electrode E3 in a planar perspective view) of the first conductor C1 of the multilayer group G6 described above. The first via V1 of the multilayer group G7 may be disposed adjacent to the fourth through hole T4 in a planar view from the stacking direction at a distance that ensures insulation from the fourth through hole T4. The first via V1 of the multilayer group G7 may be provided on the side of the magnetic layer ML opposite to the first via V1 of the multilayer group G5 in a planar perspective view.

[0047] The second via V2 of the multilayer group G7 may be disposed at a position connected to one end (the end close to the first external electrode E1 in a planar perspective view) of the second conductor C2 of the multilayer group G4 described above. The second via V2 of the multilayer group G7 may be disposed adjacent to the second through hole T2 in a planar view seen from the stacking direction at a distance that ensures insulation from the second through hole T2. The second via V2 of the multilayer group G7 may be provided on the side of the magnetic layer ML opposite to the second via V2 of the multilayer group G5 in a planar perspective view.

[0048] The second through hole T2 of the multilayer group G7 may be electrically connected to the second external electrode E2 by connecting the second through holes T2 of the multilayer groups G6 and G8 adjacent to each other in the stacking direction. Therefore, the second through hole T2 may be disposed at a corner of the magnetic layer ML located on the second external electrode E2 in a planar perspective view.

[0049] The fourth through hole T4 of the multilayer group G7 may be electrically connected to the fourth external electrode E4 by connecting the fourth through holes T4 of the multilayer groups G6 and G8 adjacent to each other in the stacking direction. Therefore, the fourth through hole T4 may be disposed at a corner of the magnetic layer ML located on the fourth external electrode E4 in a planar perspective view.

[0050] The multilayer group G8 may include a magnetic layer ML, a first conductor C1 and a second conductor C2 arranged in the same layer, a second through hole T2, and a fourth through hole T4. The area of ​​the first conductor C1 in a plan view from the stacking direction in the same layer is approximately equal to the area of ​​the second conductor C2 in a plan view from the stacking direction. Here, approximately equal includes a range of ±10%, and may be within ±5%, more preferably.

[0051] The first conductor C1 of the multilayer group G8 may be connected to the first conductor C1 of the multilayer group G6 through the first via V1 of the multilayer group G7, and may constitute a part of the winding of the first coil 21. Specifically, the first conductor C1 of the multilayer group G8 may be along at least one side of the magnetic layer ML located opposite to the side of the magnetic layer ML along the first conductor C1 of the multilayer group G6 in a plan view seen from the stacking direction, and may have an avoiding portion A that avoids the fourth through hole T4. One end of the first conductor C1 (at a position close to the first external electrode E1 in a planar perspective view) may be provided with a first through hole (not shown) that connects to the first external electrode E1. The other end of the first conductor C1 (at a position close to the third external electrode E3 in a planar perspective view) may be connected to the first via V1 of the multilayer group G7.

[0052] The second conductor C2 of the multilayer group G8 may be connected to the second conductor C2 of the multilayer group G6 through the second via V2 of the multilayer group G7, and may constitute a part of the winding of the second coil 22. Specifically, the second conductor C2 of the multilayer group G8 may be along at least one side of the magnetic layer ML located opposite to the side of the magnetic layer ML along the second conductor C2 of the multilayer group G6 in a plan view seen from the stacking direction, and may have an avoiding portion A that avoids the second through hole T2. One end of the second conductor C2 (a position close to the first external electrode E1 in a planar perspective view) may be connected to the second via V2 of the multilayer group G7. In addition, a third through hole (not shown) that connects to the third external electrode E3 may be provided at the other end of the first conductor C1 (a position close to the third external electrode E3 in a planar perspective view).

[0053] The multilayer group G9 may include a magnetic layer ML, a first through hole T1, a second through hole T2, a third through hole, and a fourth through hole T4. The areas of the first through holes T1 to the fourth through holes T4 of the multilayer groups G1 to G9 in a plan view from the stacking direction may be approximately the same.

[0054] The multilayer group G10 may include a magnetic layer ML, a first through hole T1, a second through hole T2, a third through hole, and a fourth through hole T4. The area of ​​the first through hole T1 to the fourth through hole T4 of the multilayer group G10 in a plan view from the stacking direction may be larger than the area of ​​the first through hole T1 to the fourth through hole T4 of the multilayer group G10 in a plan view from the stacking direction of the multilayer group G10, and the thickness of the multilayer group G10 may be smaller than the thickness of the multilayer group 9. By making the planar area of ​​the first through hole T1 to the fourth through hole T4 of the multilayer group G10 larger than the first external electrode E1 to the fourth external electrode E4, even if thermal shrinkage occurs due to firing, alignment with the first external electrode E1 to the fourth external electrode E4 can be easily performed.

[0055] Here, the thickness of the first conductor C1 and / or the second conductor C2 in each lamination group may be the same. The first conductor C1 and / or the second conductor C2 may be a metal conductor such as Ag and / or Cu as an example of the material. The first conductor C1 and / or the second conductor C2 may be formed, for example, by printing a conductive paste on the above-mentioned magnetic layer ML.

[0056] An example of the material of the first to fourth through holes T4, the first via V1, and the second via V2 may be a metal conductor such as Ag and / or Cu. The material of the first to fourth through holes T4, the first via V1, and the second via V2 may be the same type of material as the first conductor C1 and / or the second conductor C2, or a different type of material. The through holes and via conductors may be formed, for example, by forming a through hole in the magnetic layer ML and printing a conductive paste in the through hole, or may be formed by printing the conductive paste and then printing the magnetic layer ML outside the conductive paste.

[0057] As described above, when the element body 10 has a multilayer structure including the multilayer groups G1 to G10, the degree of freedom in designing the multilayer inductor 1A is increased. For example, when manufacturing a multilayer inductor 1A including the first external electrode E1, the second external electrode E2, the third external electrode E3, and the fourth external electrode E4 on the bottom surface (first main surface 11) of the element body 10, it becomes easier to draw out the first coil 21 and the second coil 22 to the bottom surface side. The multilayer structure including the multilayer groups G1 to G10 may be formed by stacking the material constituting the magnetic layer ML, the material constituting the first conductor C1 or the second conductor C2, and the material constituting the through-holes and / or vias by sequentially printing (for example, screen printing, etc.) from the second main surface 12 side or the first main surface 11 side of the element body 10. In this case, each of the multilayer groups G1 to G10 may be repeatedly printed until the magnetic layer ML, the first conductor C1 and / or the second conductor C2, the through-holes and / or the vias reach a desired thickness.

[0058] Furthermore, one of the features of the laminated inductor 1A of the present disclosure is that, in the laminated groups G1 to G10, the area of ​​the first conductor C1 in a plan view seen from the lamination direction in the same layer is approximately equal to the area of ​​the second conductor C2 in a plan view seen from the lamination direction. Here, approximately equal includes a range of ±10%, and more preferably may be within ±5%. Therefore, it is possible to reduce the difference between the wiring resistance and inductance value caused by the area of ​​the first conductor C1 in a plan view seen from the lamination direction and the wiring resistance and inductance value caused by the area of ​​the second conductor C2 in a plan view seen from the lamination direction.

[0059] Furthermore, one of the features of the laminated inductor 1A of the present disclosure is that the first conductor C1 and the second conductor C2 are alternately arranged when viewed from a direction intersecting the lamination direction. More specifically, in Fig. 2 and Fig. 3, when the element body 10 is seen through from the length direction L (or width direction W), there is a region R1 (see Fig. 2) in which the first conductor C1 and the second conductor C2 are alternately arranged. In this way, when the first conductor C1 and the second conductor C2 are provided in the same layer, the areas of the first conductor C1 and the second conductor C2 are approximately equal in a plan view seen from the lamination direction, and the first conductor C1 and the second conductor C2 are alternately arranged when viewed from a direction intersecting the lamination direction. This, combined with the fact that the first conductor C1 and the second conductor C2 are provided in an identical layer, the reduction in the difference between the wiring resistance and the inductance value can be understood from the viewpoints of the shapes and arrangements of the first conductor C1 and the second conductor C2 when viewed from the lamination direction (plan view seen from the lamination direction) and when viewed from a direction intersecting the lamination direction.

[0060] Additional elements of the element body 10 will be described. The magnetic layer ML may include metal magnetic particles made of a magnetic material. The metal magnetic particles may include Fe and / or Si. More specifically, they may be Fe particles or Fe alloy particles. The Fe alloy may be an Fe-Si alloy, an Fe-Si-Cr alloy, an Fe-Si-Al alloy, an Fe-Si-BP-Cu-C alloy, an Fe-Si-B-Nb-Cu alloy, or the like. The metal magnetic particles may also include impurities such as Cr, Mn, Cu, Ni, P, S, or Co that are not intended in the manufacturing process. The metal magnetic particles may also be included in the magnetic paste. Therefore, the metal magnetic particles may include an element (e.g., Cr, Al, Li, Zn) that is more easily oxidized than Fe added when the magnetic paste is prepared.

[0061] The surface of the above-mentioned metal magnetic particles may be covered with an insulating film (not shown). When the surface of the metal magnetic particles is covered with an insulating film, the insulation between the metal magnetic particles can be improved. The method of forming the insulating film on the surface of the metal magnetic particles may be a sol-gel method, a mechanochemical method, or the like. The material constituting the insulating film may be an oxide of P, Si, or the like, zinc phosphate, or manganese phosphate. The insulating film may also be an oxide film formed by oxidizing the surface of the metal magnetic particles. The thickness of the insulating film is preferably 1 nm or more and 50 nm or less, more preferably 1 nm or more and 30 nm or less, and even more preferably 1 nm or more and 20 nm or less. For example, a cross section obtained by polishing a sample of an inductor is photographed with a scanning electron microscope (SEM), and the thickness of the insulating film covering the surface of the metal magnetic particles can be measured from the obtained SEM photograph.

[0062] The average particle size of the metal magnetic particles in the magnetic layer ML is preferably 1 μm or more and 30 μm or less, more preferably 1 μm or more and 20 μm or less, and even more preferably 1 μm or more and 10 μm or less. The average particle size of the metal magnetic particles in the magnetic layer can be measured by the procedure described below. The inductor sample is cut to obtain a sample cross section. Specifically, the sample cross section is obtained by cutting through the center of the element body so as to be perpendicular to the mounting surface and end surface of the element body. For the obtained cross section, multiple (e.g., 5) areas (e.g., 130 μm x 100 μm) are photographed by SEM, and the obtained SEM images are analyzed using image analysis software (e.g., image analysis software WinROOF2021 (manufactured by Mitani Shoji Co., Ltd.)) to obtain the circle equivalent diameter of the metal magnetic particles. The average value of the obtained circle equivalent diameters is taken as the average particle size of the metal magnetic particles.

[0063] When forming the element body 10, a heat treatment is performed. In this case, the metal magnetic particles contained in the element body 10 have an oxide film on the surface. This oxide film originates from the metal magnetic particles and is formed by the heat treatment. In the element body 10, adjacent metal magnetic particles may be joined to each other via the oxide film.

[0064] In order to further improve the strength of the element body 10, the element body 10 may be impregnated with a resin material after firing the element body 10. As an example of a resin that increases the strength of the element body, an epoxy resin and / or a phenol resin and / or a silicone resin may be used.

[0065] -External electrode- The external electrodes are provided on the bottom surface of the element body 10. The external electrodes include a first external electrode E1, a second external electrode E2, a third external electrode E3, and a fourth external electrode E4. The first external electrode E1 and the second external electrode E2 may be electrically connected to the first coil 21. The third external electrode E3 and the fourth external electrode E4 may be electrically connected to the second coil 22. Providing the external electrodes on the bottom surface (first main surface 11) of the element body 10 makes it possible to properly mount the laminated inductor 1A on a mounting board or the like.

[0066] The first external electrode E1 may act as an input electrode and / or an output electrode for the first coil 21. The first external electrode E1 may be provided only on the first main surface 11 of the element body 10, or may be provided across the first main surface 11 of the element body 10 and at least one of the second end surface 14, the first side surface 15, or the second side surface 16.

[0067] The second external electrode E2 may act as an input electrode and / or an output electrode for the second coil 22. The second external electrode E2 may be provided only on the first main surface 11 of the element body 10, or may be provided across at least one of the first main surface 11, the first end surface 13, and / or the first side surface 15 of the element body 10.

[0068] The third external electrode E3 may act as an input electrode and / or an output electrode for the second coil 22. The third external electrode E3 may be provided only on the first main surface 11 of the element body 10, or may be provided across at least one of the first main surface 11, the first end surface 13, and / or the second side surface 16 of the element body 10.

[0069] The fourth external electrode E4 may act as an input electrode and / or an output electrode for the second coil 22. The fourth external electrode E4 may be provided only on the first main surface 11 of the element body 10, or may be provided across at least one of the first main surface 11, the second end surface 14, and / or the first side surface 15 of the element body 10.

[0070] In a preferred embodiment of the external electrodes, the planar area of ​​the external electrodes as viewed from the mounting surface side of the element body 10 may be smaller than the planar area of ​​the first through hole T1 to the fourth through hole T4 of the multilayer group G10. Making the planar area of ​​the external electrodes smaller than the first through hole T1 to the fourth through hole T4 of the multilayer group G10 facilitates connection between the external electrodes, which require a certain positional accuracy on the element body, and the through holes, which become misaligned due to thermal shrinkage caused by firing.

[0071] The external electrodes may be made of various materials such as Cu and / or Ni. The external electrodes may be formed of a single layer or may have a laminated structure of two or more layers. The external electrodes may be formed by any method, but may be plated electrodes formed by plating (e.g., electroless plating), for example.

[0072] -First coil- The first coil 21 is provided inside the element body 10. The first coil 21 provided inside the element body 10 includes a first winding portion W1 formed by connecting respective ends of a plurality of first conductors C1 arranged on different layers of the element body 10 by first vias V1, a first through hole T1, and a second through hole T2.

[0073] The first winding portion W1 may be configured by the first conductors C1 and the first vias V1 provided in the multilayer groups G2 to G8. Specifically, the first winding portion W1 may be wound counterclockwise with respect to the second external electrode E2.

[0074] The first vias V1 may electrically connect the first conductors C1 provided in adjacent stacking groups in the stacking direction. The length of the first vias V1 in the stacking direction may be shorter than the length of the first through holes T1 or the length of the second through holes T2. The first conductors C1 may have a stacking structure.

[0075] The first through hole T1 may connect the end of the first conductor C1, which is the closest to the bottom surface (first main surface 11) of the element body 10, among the ends of the first coil 21, to the first external electrode E1. The first through hole T1 may extend along the stacking direction (e.g., the height direction T). The first through hole T1 may have a stacked structure.

[0076] The second through hole T2 may connect the other end of the first coil 21 and the second external electrode E2. The second through hole T2 may extend along the stacking direction (e.g., the height direction T). The second through hole T2 may have a stacked structure.

[0077] -Second coil- The second coil 22 is provided inside the element body 10. The second coil 22 provided inside the element body 10 includes a second winding portion W2 formed by connecting respective ends of multiple second conductors C2 arranged on different layers of the element body 10 by second vias V2, a third through hole T3, and a fourth through hole T4.

[0078] The second winding portion W2 may be configured by the second conductors C2 and the second vias V2 provided in the multilayer groups G2 to G8. Specifically, the second winding portion W2 may be wound counterclockwise with respect to the fourth external electrode E4 located diagonally opposite the second external electrode E2. In the multilayer inductor 1A of the present disclosure, in consideration of reducing the difference in DC resistance and / or inductance value between the first coil 21 and the second coil 22, the number of turns of the first winding portion W1 and the number of turns of the second winding portion W2 may be substantially the same.

[0079] The second vias V2 may electrically connect the second conductors C2 provided in the stacking groups adjacent to each other in the stacking direction. The length of the second vias V2 in the stacking direction may be shorter than the length of the third through holes T3 or the length of the fourth through holes T4. The second conductors C2 may have a stacking structure.

[0080] The third through hole T3 may connect the end of the second conductor C2, which is the end of the second coil 22 closest to the bottom surface (first main surface 11) of the element body 10, to the third external electrode E3. The third through hole T3 may extend along the stacking direction (e.g., the height direction T). The third through hole T3 may have a stacked structure.

[0081] The fourth through hole T4 may connect the other end of the second coil 22 and the fourth external electrode E4. The fourth through hole T4 may extend along the lamination direction (e.g., the height direction T). The fourth through hole T4 may have a laminated structure.

[0082] As described above, according to the present disclosure, in an inductor including multiple coils therein, it is possible to reduce the difference in the DC resistance and / or inductance value of each coil.

[0083] <Additional configuration of multilayer inductors> In the above-described laminated inductor 1A, in a plan view seen from the lamination direction, the first conductor C1 and the second conductor C2 may be in a point-symmetric relationship with respect to the center of the magnetic layer ML. Specifically, referring to Fig. 3, in the laminated groups G2, G4, G6, and G8 including the first conductor C1 and the second conductor C2, when rotated 180° around the center of the magnetic layer ML, the laminated groups G2, G4, G6, and G8 overlap each other.

[0084] With this configuration, the area of ​​the first conductor C1 in a planar view from the stacking direction within the same layer is approximately equal to the area of ​​the second conductor C2 in a planar view from the stacking direction, thereby further reducing the difference in the DC resistance and / or inductance values ​​of each coil.

[0085] In the above-mentioned laminated inductor 1A, the first conductor C1 and the second conductor C2 may overlap in an overlapping region in a plan view seen from the lamination direction. That is, the arrangement relationship between the first conductor C1 and the second conductor C2 is specified between different laminated groups. More specifically, the first conductor C1 of the laminated group G2 is arranged along two sides forming a corner of the magnetic layer ML (for example, a corner close to the third external electrode E3 in a planar perspective view), and the second conductor C2 of the laminated group G4 is arranged along a part of two sides forming a corner of the magnetic layer (for example, a corner close to the third external electrode E3 in a planar perspective view). Therefore, between the laminated group G2 and the laminated group G4, there is an overlapping region R2 where the first conductor C1 and the second conductor C2 overlap in a planar view seen from the lamination direction.

[0086] According to this configuration, the positional relationship between the first conductor C1 and the second conductor C2 is specified not only in the same stacking group but also between different stacking groups, and the first conductor C1 and the second conductor C2 have an overlapping region. As a result, the first conductor C1 and the second conductor C2 have substantially similar shapes. Therefore, the coupling between the first coil 21 and the second coil 22 can be increased.

[0087] In the above-mentioned laminated inductor 1A, the first conductor C1 may have a first avoidance portion A1 that avoids the second through hole T2, and / or the second conductor C2 may have a second avoidance portion A2 that avoids the fourth through hole T4. With this configuration, in a plan view seen from the lamination direction, the second through hole T2 and the fourth through hole T4 can be disposed at positions avoided by the first avoidance portion A1 and the second avoidance portion A2, so that the laminated inductor can be made smaller in plan view seen from the lamination direction than a laminated inductor that does not have an avoidance portion.

[0088] As a more preferable aspect of the avoidance portion, the first avoidance portion A1 may be located inside the magnetic layer ML from the second through hole T2 in a plan view seen from the stacking direction, and / or the second avoidance portion A2 may be located inside the magnetic layer ML from the fourth through hole T4 in a plan view seen from the stacking direction. With this configuration, it is possible to obtain a laminated inductor that is smaller in plan view seen from the stacking direction than a laminated inductor that does not have an avoidance portion.

[0089] In the above-described laminated inductor 1A, the first external electrode E1, the second external electrode E2, the third external electrode E3 and the fourth external electrode E4 may be provided at corners of an element body 10 that has a rectangular shape in plan view when viewed from the lamination direction. By providing the first to fourth external electrodes E4 at corners of the element body 10 that has a rectangular shape in plan view when viewed from the lamination direction, the external electrodes can be spaced as far apart as possible, thereby increasing the dielectric strength voltage between the external electrodes.

[0090] In the above-mentioned laminated inductor 1A, an insulating layer IL may be disposed between the first conductor C1 and the second conductor C2 in the lamination direction (see FIG. 5). As an example, the magnetic layers ML of the laminated groups G3, G5, and G7 shown in FIG. 3 may be replaced with an insulating layer IL. By providing the insulating layer IL between the first conductor C1 and the second conductor C2 in the lamination direction, the dielectric strength between the first conductor C1 and the second conductor C2 can be increased.

[0091] <Multilayer inductor array> Next, the laminated inductor array of the present disclosure will be described with reference to FIG. 6. The laminated inductor array 1B of the present disclosure configures a coil array by arranging a first coil and a second coil side by side in a direction intersecting the lamination direction. Specifically, in addition to the first coil 21 and the second coil 22, the array may include a third coil 23 and a fourth coil 24, as well as a fifth coil 25 and a sixth coil 26. The third coil 23 and the fifth coil 25 have substantially the same structure as the first coil 21, and the fourth coil 24 and the sixth coil 26 have substantially the same structure as the second coil 22.

[0092] The third coil 23 may be electrically connected to a fifth external electrode E5 and a sixth external electrode (not shown). Of the ends of the third coil 23, an end of the third conductor closest to the bottom surface may be connected to the fifth external electrode E5 by a fifth through hole T5. In addition, the other end of the third conductor may be connected to the sixth external electrode (not shown) by a sixth through hole T6.

[0093] The fourth coil 24 may be electrically connected to a seventh external electrode (not shown) and an eighth external electrode E8. Of the ends of the fourth coil 24, an end of the fourth conductor closest to the bottom surface may be connected to the seventh external electrode (not shown) by a seventh through hole (not shown). In addition, the other end of the fourth conductor may be connected to the eighth external electrode E8 by an eighth through hole T8.

[0094] The fifth coil 25 may be electrically connected to the ninth external electrode E9 and the tenth external electrode (not shown). Of the ends of the fifth coil 25, the end of the fifth conductor closest to the bottom surface may be connected to the ninth external electrode E9 by a ninth through hole T9. In addition, the other end of the fifth conductor may be connected to the tenth external electrode (not shown) by a tenth through hole T10.

[0095] The sixth coil 26 may be electrically connected to an eleventh external electrode (not shown) and a twelfth external electrode E12. Of the ends of the sixth coil 26, an end of the sixth conductor closest to the bottom surface may be connected to the eleventh external electrode (not shown) by an eleventh through hole (not shown). In addition, the other end of the sixth conductor may be connected to the twelfth external electrode E12 by a twelfth through hole T12.

[0096] Even in the laminated inductor array 1B of the present disclosure, the first conductor and the second conductor are provided in the same layer, the area of ​​the first conductor in a plan view seen from the stacking direction in the same layer is approximately equal to the area of ​​the second conductor in a plan view seen from the stacking direction, and the first conductor and the second conductor are arranged alternately when viewed from a direction intersecting the stacking direction, and the third conductor and the fourth conductor are provided in the same layer, the area of ​​the third conductor in a plan view seen from the stacking direction in the same layer is approximately equal to the area of ​​the fourth conductor in a plan view seen from the stacking direction, and the third conductor and the fourth conductor are arranged alternately when viewed from a direction intersecting the stacking direction. Therefore, the difference in the DC resistance and / or inductance value of each coil can be reduced.

[0097] The technical scope of the present disclosure is not interpreted only by the above-described embodiment, but is defined based on the description of the claims. The technical scope of the present disclosure includes all modifications within the meaning and scope of the claims.

[0098] The laminated inductor and laminated inductor array of the present disclosure include the following aspects. <1> an element body formed by laminating a plurality of magnetic layers in a lamination direction; a first external electrode, a second external electrode, a third external electrode and a fourth external electrode provided on a bottom surface of the element body; a first coil including a first winding portion formed by connecting respective ends of a plurality of first conductors arranged on different layers of the element body with vias, a first through hole connecting one end of the first winding portion relatively close to the bottom surface and the first external electrode, and a second through hole connecting the other end of the first winding portion relatively far from the bottom surface and the second external electrode; a second coil including a second winding portion formed by connecting respective ends of a plurality of second conductors arranged on different layers of the element body by vias, a third through hole connecting one end of the second winding portion relatively close to the bottom surface and the third external electrode, and a fourth through hole connecting the other end of the second winding portion relatively far from the bottom surface and the fourth external electrode, the first conductor and the second conductor are provided in the same layer, and an area of ​​the first conductor in a plan view in the same layer is substantially equal to an area of ​​the second conductor in a plan view; A laminated inductor, wherein the first conductors and the second conductors are arranged alternately with each other when viewed from a direction intersecting the lamination direction. <2> In a plan view, the first conductor and the second conductor are in a point-symmetric relationship with respect to a center of the magnetic layer. <1> The laminated inductor according to claim 1. <3> In a plan view, the first conductor and the second conductor overlap each other at an overlapping region. <1> or <2> The laminated inductor according to claim 1. <4> the first conductor has a first avoidance portion that avoids the second through hole, and / or the second conductor has a second avoidance portion that avoids the fourth through hole. <1> ~ <3> 13. The laminated inductor according to claim 12, <5> the first avoidance portion is located on the inner side of the magnetic layer than the second through hole in a plan view, and / or the second avoidance portion is located on the inner side of the magnetic layer than the fourth through hole in a plan view. <4> The laminated inductor according to claim 1. <6> the first external electrode, the second external electrode, the third external electrode, and the fourth external electrode are provided at corners of the element body which is rectangular in plan view, <1> ~ <5> 13. The laminated inductor according to claim 12, <7> An insulating layer is disposed between the first conductor and the second conductor in the stacking direction. <1> ~ <6> 13. The laminated inductor according to claim 12, <8> an element body formed by laminating a plurality of magnetic layers in a lamination direction; a first external electrode, a second external electrode, a third external electrode, a fourth external electrode, a fifth external electrode, a sixth external electrode, a seventh external electrode and an eighth external electrode provided on a bottom surface of the element body; a first coil including a first winding portion formed by connecting respective ends of a plurality of first conductors arranged on different layers of the element body with vias, a first through hole connecting one end of the first winding portion relatively close to the bottom surface and the first external electrode, and a second through hole connecting the other end of the first winding portion relatively far from the bottom surface and the second external electrode; a second coil including: a second winding portion formed by connecting respective ends of a plurality of second conductors arranged on different layers of the element body with vias; a third through hole connecting one end of the second winding portion relatively close to the bottom surface and the third external electrode; and a fourth through hole connecting the other end of the second winding portion relatively far from the bottom surface and the fourth external electrode; a third coil including: a third winding portion formed by connecting respective ends of a plurality of third conductors arranged on different layers of the element body with vias; a fifth through hole connecting one end of the third winding portion relatively close to the bottom surface and the fifth external electrode; and a sixth through hole connecting the other end of the third winding portion relatively far from the bottom surface and the sixth external electrode; a fourth coil including a fourth winding portion formed by connecting respective ends of a plurality of fourth conductors arranged on different layers of the element body with vias, a seventh through hole connecting one end of the fourth winding portion relatively close to the bottom surface and the seventh external electrode, and an eighth through hole connecting the other end of the fourth winding portion relatively far from the bottom surface and the eighth external electrode, the third coil and the fourth coil are adjacent to each other in a direction intersecting the stacking direction with respect to the first coil and the second coil, the first conductor and the second conductor are provided in the same layer, and an area of ​​the first conductor in a plan view in the same layer is substantially equal to an area of ​​the second conductor in a plan view; When viewed from a direction intersecting the stacking direction, the first conductors and the second conductors are arranged alternately with each other, the third conductor and the fourth conductor are provided in the same layer, and an area of ​​the third conductor in a plan view in the same layer is substantially equal to an area of ​​the fourth conductor in a plan view; a laminated inductor array in which the third conductors and the fourth conductors are arranged alternately when viewed from a direction intersecting the lamination direction. [Industrial Applicability]

[0099] The present disclosure can be used for a laminated inductor and a laminated inductor array that can reduce the difference in the DC resistance and / or inductance value of each coil in an inductor having multiple coils therein. [Explanation of symbols]

[0100] 1A Multilayer Inductor 1B Multilayer inductor array 10 Base 11 First main surface 12 Second main surface 13 First end surface 14 Second end face 15 First aspect 16 Second aspect 21~26 1st coil~6th coil A Avoidance part A1 First Avoidance Section A2 2nd avoidance part C1 First conductor C2 Second conductor E1~E12 1st external electrode ~ 12th external electrode T1~T12 1st through hole~12th through hole V-Via V1 First via V2 Second via W1 Volume 1 W2 Volume 2 ML magnetic layer IL Insulation layer R1,R2 area

Claims

1. an element body formed by laminating a plurality of magnetic layers in a lamination direction; a first external electrode, a second external electrode, a third external electrode and a fourth external electrode provided on a bottom surface of the element body; a first coil including: a first winding portion formed by connecting respective ends of a plurality of first conductors arranged on different layers of the element body with vias; a first through hole connecting one end of the first winding portion relatively close to the bottom surface and the first external electrode; and a second through hole connecting the other end of the first winding portion relatively far from the bottom surface and the second external electrode; a second coil including a second winding portion formed by connecting respective ends of a plurality of second conductors arranged on different layers of the element body by vias, a third through hole connecting one end of the second winding portion relatively close to the bottom surface and the third external electrode, and a fourth through hole connecting the other end of the second winding portion relatively far from the bottom surface and the fourth external electrode, the first conductor and the second conductor are provided in the same layer, and an area of ​​the first conductor in a plan view in the same layer is substantially equal to an area of ​​the second conductor in a plan view; A laminated inductor, wherein the first conductors and the second conductors are arranged alternately with each other when viewed from a direction intersecting the lamination direction.

2. The laminated inductor according to claim 1 , wherein, in a plan view, the first conductor and the second conductor are in a point-symmetric relationship with respect to a center of the magnetic layer.

3. The multilayer inductor according to claim 1 , wherein, in a plan view, the first conductor and the second conductor overlap each other at an overlapping region.

4. The laminated inductor according to claim 1 , wherein the first conductor has a first avoidance portion that avoids the second through hole, and / or the second conductor has a second avoidance portion that avoids the fourth through hole.

5. The laminated inductor according to claim 4 , wherein the first avoidance portion is located inside the magnetic layer relative to the second through hole in a planar view, and / or the second avoidance portion is located inside the magnetic layer relative to the fourth through hole in a planar view.

6. 2. The multilayer inductor according to claim 1, wherein the first external electrode, the second external electrode, the third external electrode and the fourth external electrode are provided at corners of the element body which is rectangular in plan view.

7. The multilayer inductor according to claim 1 , wherein an insulating layer is disposed between the first conductor and the second conductor in the stacking direction.

8. an element body formed by laminating a plurality of magnetic layers in a lamination direction; a first external electrode, a second external electrode, a third external electrode, a fourth external electrode, a fifth external electrode, a sixth external electrode, a seventh external electrode and an eighth external electrode provided on a bottom surface of the element body; a first coil including: a first winding portion formed by connecting respective ends of a plurality of first conductors arranged on different layers of the element body with vias; a first through hole connecting one end of the first winding portion relatively close to the bottom surface and the first external electrode; and a second through hole connecting the other end of the first winding portion relatively far from the bottom surface and the second external electrode; a second coil including: a second winding portion formed by connecting respective ends of a plurality of second conductors arranged on different layers of the element body with vias; a third through hole connecting one end of the second winding portion relatively close to the bottom surface and the third external electrode; and a fourth through hole connecting the other end of the second winding portion relatively far from the bottom surface and the fourth external electrode; a third coil including: a third winding portion formed by connecting respective ends of a plurality of third conductors arranged on different layers of the element body with vias; a fifth through hole connecting one end of the third winding portion relatively close to the bottom surface and the fifth external electrode; and a sixth through hole connecting the other end of the third winding portion relatively far from the bottom surface and the sixth external electrode; a fourth coil including a fourth winding portion formed by connecting respective ends of a plurality of fourth conductors arranged on different layers of the element body by vias, a seventh through hole connecting one end of the fourth winding portion relatively close to the bottom surface and the seventh external electrode, and an eighth through hole connecting the other end of the fourth winding portion relatively far from the bottom surface and the eighth external electrode, the third coil and the fourth coil are adjacent to each other in a direction intersecting the stacking direction with respect to the first coil and the second coil, the first conductor and the second conductor are provided in the same layer, and an area of ​​the first conductor in a plan view in the same layer is substantially equal to an area of ​​the second conductor in a plan view; When viewed from a direction intersecting the stacking direction, the first conductors and the second conductors are arranged alternately with each other, the third conductor and the fourth conductor are provided in the same layer, and an area of ​​the third conductor in a plan view in the same layer is substantially equal to an area of ​​the fourth conductor in a plan view; a laminated inductor array, wherein the third conductors and the fourth conductors are arranged alternately with each other when viewed from a direction intersecting the lamination direction.

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